Browsing by Author "S. Dubey"

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Diurnal variations in circulating estradiol, testosterone, melatonin and Harderian gland porphyrin concentration in Indian palm squirrel, Funambulus pennanti
(1996) C. Haldar; S. Dubey
A two-peak cyclicity in the plasma level of melatonin, estradiol/testosterone and Harderian porphyrin was noted in F. pennanti. An inverse relationship of Harderian porphyrin with plasma melatonin and a direct relation of it with plasma estradiol/testoserone level were also observed, suggesting that the variation of Harderian porphyrin concentration may be under the control of both, circulating melatonin and gonadal steroids.
Electrochemical synthesis and properties of poly(3-methylthiophene): Novel synthesis of poly(3-methylthiophene) with pentachlorostannate and hexachloroantimonate
(John Wiley & Sons Inc, 1999) Dan Singh; S. Dubey; B.M. Prasad; R.A. Misra
Poly(3-methylthiophene) (P3-MeT) doped with different anions were prepared electrochemically in the presence of tetraalkylammonium salts. The new poly(3-methylthiophene) SnCl5- and SbCl6- (P3-MeT SnCl5 and P3-MeT SbCl6) were prepared electrochemically using tetra-n-butylammonium pentachlorostannate and tetra-n-butylammonium hexachloroantimonate as the supporting electrolytes. The effect of current density, salt concentration, reaction temperature, and the nature of solvents on the polymer yield and polymer conductivities have been investigated. Cyclic voltammetry of poly(3-methylthiophene) has been examined at platinum electrode in 1,2-dichloroethane medium containing n-Bu4NSnCl5, Bu4NSbCl6, and Bu4NClO4 as the supporting electrolytes in the range of -1.0 to 1.7 V versus SCE in the presence and absence of 3-methylthiophene. Electrical conductivity, magnetic susceptibility measurements, and structural determination by elemental analysis and infrared studies were also made. Scanning electron microscopy revealed a globular, branched, fibrous and a spongy, fibrous morphology of poly(3-methylthiophene) SnCl5-, ClO4, and SbCl6-, respectively. The thermal analysis of the polymers was also investigated. Possible causes for the observed lower conductivity of these polymers have also been discussed.
Environmental factors and annual Harderian-pineal-gonadal interrelationship in Indian jungle bush quail, Perdicula asiatica
(Academic Press Inc., 1997) S. Dubey; C. Haldar
A functional link between the Harderian and pineal glands has been suspected because they both are known to respond to changes in photoperiod. Further, the pineal gland is known to influence reproduction by secreting melatonin, and melatonin receptors have been detected in the Harderian gland. Hence, we conducted a study to investigate the annual changes in weight and secretory activity for the pineal gland, Harderian gland, and ovary in jungle bush quail (Perdicula asiatica), a bird indigenous to the tropics in India. Annual changes in weight for the three glands were found. In late May, when weather is favorable, the ovary and Harderian gland reached maximal mass, and the pineal gland had the smallest mass. In general, the annual changes in weight for the three glands were associated with the annual changes in melatonin and 17β-estradiol concentrations in the plasma and porphyrin content in the Harderian gland. These results suggest that there is an inverse relationship between pineal gland activity and ovarian and Harderian gland activities.
Oxidative synthesis and properties of poly(2-ethylaniline)
(1999) R.A. Misra; S. Dubey; B.M. Prasad; Dan Singh
Poly(2-ethylaniline), a π-electron conjugated conducting polymer, has been prepared under different polymerization conditions in nitrogen atmosphere. The structure of the prepared polymer has been elucidated by infrared spectra and elemental analyses. The electrochemical studies of the polymerization of 2-ethylaniline and its film at a platinum electrode have been performed in 1,2-dichloroethane using different dopants. The electrical conductivities of these polymers are found to be in the range of 10-4 to 10-7 Scm-1. Thermal studies of the polymer were carried out by thermogravimetric analysis. The DTG curves of Cl O4/- and SbCl6/- doped polymer reveal the maximum weight loss at 400 and 500°C respectively. The magnetic susceptibility of the prepared polymer shows paramagnetic behaviour. Surface morphology of the polymer film is also described.
Povidone-iodine (Betadine) as prophylaxis against wound infection in abdominal tubal ligation
(1984) A. Khanna; S. Dubey
Povidone-iodine solution was used for this prospective study by including 100 patients who underwent abdominal tubal ligation by a small, vertical, suprapubic incision. In the test group of 50 patients a thin layer of povidone-iodine (5%) was painted over the skin around the incision and it was left as such for 5 minutes. Then part preparation was done by savalon and spirit. A layer of povidone (5%) was instilled in the wound. The wound was cleanded with spirit and then a povidone-iodine (5%) soaked gauge piece was applied and dressings were done. No postoperative antibiotics were given. In the 50-patient group, a similar procedure was performed but without povidone-iodine. Postoperative antibiotics were given to these patients until the stitches were removed. The wound was opened after 48 hours in both groups and then checked at 48-hour intervals. If the wound showed any evidence of infection, the dressing was done at 24-hour intervals. In cases of infected wounds, povidone-iodine (5%) ointment dressing was done in the test group; dressing was done by other antibacterial ointments in the control group. The wound infection rate was comparable in both groups. 4 of 50 (87%) test group patients had wound infection in the form of stitch abscess and serious discharge, which was rapidly controlled by povidone-iodine dressing in 3 days time on average. 3 of 50 (6%) control group patients had wound infection, which was controlled by local dressing in 4-5 days on average. There was no statistically significant difference between the 2 groups. It is concluded that povidone-iodine solution is preferable to routine use of postoperative antibiotics in minor operations. It is well tolerated with no untoward reactions and is an inexpensive modality for preventing infection.
Regulation of Harderian gland porphyrin by pineal gland and melatonin in Indian Palm Squirrel, Funambulus pennanti
(1997) S. Dubey; C. Haldar
Daily administration of 25 μg of melatonin (MEL) for 30 days during reproductive active phase May-June) of F. pennanti, decreased the Harderian gland porphyrin (HG-porphyrin) concentration and gonadal function without effecting the Harderian gland (HG) weight. Further, pinealectomy (Px) performed during same reproductive phase could not bring any significant change in Harderian and gonadal function of either sexes as they were in full activity. Therefore, it may be suggested that HG-porphyrin is negatively regulated by MEL and thereby inversely related with the pineal gland function.